Characterization of Local Nano-Heat Transfer Fluids for Solar Thermal Collection

Table 4

Average variation of heat coefficient with steam flow rate.

Fluid	Heat coefficient (W/m^2°C) (average)	Steam flow rate (kgs^−1) (average)
Unused engine oil	290.1	7.49
Used engine oil	284.4	6.53
Coconut oil	279.6	5.61
Sunflower oil	267.1	4.67
Castor oil	254.5	3.69